Helicobacter pylori (H. pylori) is a gram-negative bacterium, first identified in 1983. It is a spiral-shaped bacterium that grows in the mucus layer that coats the inside of the human stomach. To survive in the harsh, acidic environment of the stomach, Helicobacter pylori secretes an enzyme called urease, which converts the chemical urea to ammonia. The production of ammonia around Helicobacter pylori neutralizes the acidity of the stomach, making it more hospitable for the bacterium. In addition, the helical shape of Helicobacter pylori allows it to burrow into the mucus layer, which is less acidic than the inside space, or lumen, of the stomach. Helicobacter pylori can also attach to the cells that line the inner surface of the stomach. Although immune cells that normally recognize and attack invading bacteria accumulate near sites of Helicobacter pylori infection, they are unable to reach the stomach lining. In addition, Helicobacter pylori has developed ways of interfering with local immune responses, making them ineffective in eliminating the bacteria.

Prevalence ofHelicobacter pyloriHelicobacter pylori has coexisted with humans for many thousands of years and infection with the bacterium is common. The Centers for Disease Control and Prevention (CDC) estimates that approximately two-thirds of the world’s population harbors the bacterium, with infection rates much higher in developing countries than in developed nations. Helicobacter pylori infection does not cause illness in most infected people, but it is a major risk factor for peptic ulcer disease and is responsible for the majority of ulcers of the stomach and upper small intestine. Helicobacter pylori is a major cause of gastric (stomach) cancer and is associated with an increased risk of gastric mucosa-associated lymphoid tissue (MALT) lymphoma.

Spread of Helicobacter pylori is thought to occur through contaminated food and water or through direct mouth-to-mouth contact. In most populations, the bacterium is first acquired during childhood. Children living in crowded conditions and with a lower socioeconomic status are more likely to become infected. Per the CDC, persons with active gastric or duodenal ulcers or documented history of ulcers should be tested for Helicobacter pylori, and if found to be infected, they should be treated.

Noninvasive Tests for the Diagnosis ofHelicobacter pyloriA variety of noninvasive tests for the diagnosis of Helicobacter pylori are available. These include urea breath testing (UBT), stool antigen testing, and serology. The breath test and stool test more accurately detect Helicobacter pylori than the blood test. In patients who do not require endoscopic evaluation for evaluation of new onset dyspepsia (those under age 55 who do not have alarm symptoms), initial diagnosis of Helicobacter pylori should be made with a test for active infection (stool antigen or urea breath test). Serology, as it cannot differentiate between past or current infection and has a low positive predictive value in much of the United States, is not recommended in patients with a low pre-test probability.

Laboratory-based serologic testing using ELISA technology to detect IgG antibodies is inexpensive, noninvasive; however, concerns over its accuracy have limited its use. Large studies have found uniformly high sensitivity (90 to 100 percent), but variable specificity (76 to 96 percent); the accuracy has ranged from 83 to 98 percent. Serologic tests require validation at the local level, which is impractical in routine practice. Local prevalence of Helicobacter pylori affects the positive predictive value (PPV) of antibody testing. In areas where the prevalence of Helicobacter pylori is less than 20 percent, as in much of the United States, a positive result on serologic testing represents active infection approximately 50 percent of the time. As the low accuracy of serology would result in inappropriate treatment in significant numbers of patients, guidelines recommend that serologic testing should not be used in low prevalence populations; testing for active infection with stool antigen assay or UBT is recommended in these populations.

In patients with newly diagnosed Helicobacter pylori infection without prior treatment, the differentiation between past or present infection is not relevant. Therefore, serologic tests are appropriate in the initial workup of the patient. However, it cannot be used to see if the infection has been eradicated because the test remains positive for years even if the infection is cured. As a result, in a patient with a prior history of treated Helicobacter pylori with recurrent symptoms, a serologic test will not be informative.

Dyspepsia presents with a range of symptoms originating in upper gastrointestinal tract which may include the following:

upper abdominal pain, discomfort, or, burning sensation

postprandial fullness

early satiety

nausea

retching and/or vomiting

belching

bloating

Investigative service is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized by certifying boards and/or approving or licensing agencies or published peer review criteria as standard, effective medical practice for the treatment of the condition being treated and as such therefore is not considered medically necessary.

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.